🧪 test: add test for Splash screen timeout

[artosien]

🎯 What: The testing gap addressed
The Splash screen had a missing test for its delayed navigation functionality. A test file Splash.test.tsx was created.

📊 Coverage: What scenarios are now tested

• The Splash screen renders without crashing.
• After 3 seconds, it navigates to /home.
• The timeout is cleared upon unmounting the component.

✨ Result: The improvement in test coverage
The app now correctly tests for the delayed navigation in Splash.tsx component, catching any possible regressions in the timeout configuration. Additionally, vitest, @testing-library/react, and jsdom are now correctly set up.

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PR created automatically by Jules for task 1641244016146499975 started by @artosien

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